Revert "Merge branch 'yorick/clean-up-merge-request-diff-commits-migration' into 'master'"

Luke Duncalferequested to merge
revert-6665b71e into master

What does this MR do and why?

This MR reverts !72219 (merged) due to the CleanUpMigrateMergeRequestDiffCommitUsers migration being unable to complete on staging gitlab-com/gl-infra/production#5799 (closed).

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

Edited by Luke Duncalfe

Merge request reports